Assessing the environmental impact of resource recovery from dairy manure.

Autor: Glover CJ; Department of Chemical and Materials Engineering, University of Nevada, Reno, Reno, NV, USA. Electronic address: callang@unr.edu., McDonnell A; Department of Agricultural and Resource Economics, University of Connecticut, Storrs, CT, USA. Electronic address: alyssa.mcdonnell@unconn.edu., Rollins KS; Department of Agricultural and Resource Economics, University of Connecticut, Storrs, CT, USA. Electronic address: kimberly.rollins@unconn.edu., Hiibel SR; Department of Chemical and Materials Engineering, University of Nevada, Reno, Reno, NV, USA. Electronic address: shiibel@unr.edu., Cornejo PK; Civil Engineering Department, California State University, Chico, Chico, CA, USA. Electronic address: pcornejo-warner@csuchico.edu.
Jazyk: angličtina
Zdroj: Journal of environmental management [J Environ Manage] 2023 Mar 15; Vol. 330, pp. 117150. Date of Electronic Publication: 2023 Jan 04.
DOI: 10.1016/j.jenvman.2022.117150
Abstrakt: Manure management is a major contributor to environmental impacts from large-scale dairy production. In this study, technologies for recovering energy, nutrients, and water from dairy manure were evaluated using life cycle assessment (LCA) and compared to conventional practices on California dairy farms. Six scenarios were evaluated: conventional manure management practices, anaerobic digestion (AD) for biogas recovery, and four scenarios for nutrients, energy, and water integrated recovery, called NEWIR. The NEWIR system consists of hydrothermal carbonization (HTC) for energy recovery via hydrochar, algae cultivation in the HTC aqueous product for nutrient recovery and production of protein-rich cattle feed, and water recovery from algae pond effluent via membrane distillation. Four NEWIR scenarios were evaluated, each with a different species of algae. Based on the results of the LCA, AD improves GHG emissions relative to conventional practices by 82%, but has similar eutrophication impacts, posing similar concerns for nutrient management as current practices. Results for the NEWIR system are highly dependent on the algae species used. Three of the four species evaluated (Chlamydomonas reinhardtii, Chlorella vulgaris, and Scenedesmus obliquus) improve GHG emissions by 420-500 kg CO 2 -eq. per functional unit, while net water consumption is increased by approximately 75% over AD and conventional practices Spirulina maxima requires more water and chemical inputs for cultivation than the other species, resulting in higher water use (21 times higher than baseline), though GHG emissions are still reduced by 85 kg CO 2 -eq. per functional unit relative to conventional practices. All NEWIR scenarios improve eutrophication impacts relative to AD and conventional practices by 16-46% for marine eutrophication and 18-99% for freshwater eutrophication, depending on the algae species used. The results suggest integrated resource recovery through NEWIR is a promising treatment method for manure to mitigate GHG emissions and improve nutrient management on large-scale farms. In addition, carbon and nutrient trading policies are discussed in relation to resource recovery technologies and their potential to incentivize producers to recover products from dairy manure.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)
Databáze: MEDLINE
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